I see what you mean - clever work. Still needs two power supplies which is a bit of a pain.
I am not really qualified to answer your question, but I think they are DC coupled because the two +B in your circuit are effectively at AC ground.

One observation I would make is that those CCS can take a brutal burst of voltage on switch on and many are not up to the job. I had to use the IXY 900V chips in my Tabor clone.